Resonance scattering analysis of at least 3-component (3-C) VSP data
detects heterogeneities in the proximity of a borehole. A method for
seismic exploration of a pre-determined volume of the earth for assessing
features of the volume using at least 3-C VSP data generated for the
volume comprises: computing a resonance spectra indicating resonance
scattering of the at least 3-C VSP data; and determining a lateral
continuity of said features in accordance with the resonance spectra.
Zero amplitude in a resonance spectrum indicates definite polarization of
the direct pressure wave into the ray direction and very weak lateral
heterogeneity along the path of the direct wave. High amplitudes in a
resonance spectrum are observed if energy of the direct wave is observed
on the horizontal components due to scattering at small-scale lateral
heterogeneities near the receiver. Peak frequency provides information on
the size and location of the scattering structure.